The Atletico Madrid loanee has been provided with just four starts and two substitute outings since making the temporary switch to Stamford Bridge.
However, while the 27-year-old was withdrawn at half time of last week's fixture at Watford, Tuchel feels that the game at Vicarage Road was another match which did not suit the Spaniard.
Speaking to reporters at a press conference, Tuchel said: "He is one of the guys who needs minutes and rhythm. He is always in our thinking. We always reflect on every single training session and performance. He is one of the guys we think about, of course.
"I think he has struggled a bit with the intensity. I think he was a bit unlucky in that he played against Aston Villa, Southampton and Watford, and all three, if you look at the data, were high-intensity games, above the average in the Premier League.
"They did not suit his main qualities, but we try to encourage him because he grows into Chelsea more and more, and we will try to bring out the best and help the team."